Microsoft has been surprisingly coy about the Nvidia GPU it announced was powering the high-end version of its Surface Book tablet. We knew it was from that particular manufacturer and we knew it was located in the keyboard section — meaning that the Skylake CPU’s Intel HD or Iris GPU took over in the event of it being detached — but beyond that, information is quite thin on the ground.

However now there’s been a suggestion that in fact, the discrete GPU may be a modified Maxwell graphics chip with a gigabyte of video memory, potentially with performance in the region of a 950M.

This is all unconfirmed mind you, and it’s worth considering that this comes from Microsoft-News without a source reference, so take this with a pinch of salt until we hear otherwise.

While this is all up in the air though, we do know quite a bit about the Surface Book itself. Our own Jeremy Kaplan had a go on one a few days ago and proclaimed it not only Microsoft’s first laptop ever, but one of the lightest and fastest he’d ever used.

This is thanks to the on-board i5 or i7 CPU (depending on buyer preference) which is twinned with up to 16GB of RAM and as much as a terabyte of SSD storage space. It also has a unique fulcrum to control the pitch of the screen (which can be anything up to 3,000 x 2,000) and a magnetic connector between it and the keyboard to hold it in laptop mode.

However, users can also detach the keyboard to create a more versatile tablet, though it will switch over at that point to the CPU’s companion graphics chip. While still capable, that will be a big drop off on GPU performance, so tablet gaming may be best with the keyboard folded away, rather than detached.

We’ll learn more about the Surface Book during the team’s Reddit AMA next week. You can pre-order a Surface now, starting at $1,500.